Milling-cutter



E. A. COWLES. MILLING CUTTER.

APPLICATION FILED NOV-"H1 I920.

Patented Sept. 20, 1921.

.UNITED STATES. PATENT OFFICE.

EDWARDVA. oowLns, OF'CLEVELANRIOHIVO. l

mLmNG-cU'rrER.

My invention relates to a milling cutter and more particularly to what I believe to be an improved manner of securing a, detachable blade.

Being in the business of manufacturing milling cutters I am familiar with previous practices and with many other schemes which may never have been commercially demonstrated. It is common practice to provide the periphery of a cutter head with two kinds of slots alternatively arranged therearound. Blades are inserted in one set of slots and wedge pins cause the material between the slots to spring over against 7 and bind the inserted blade.

I declare my knowledge of the fact that screws have been employed to directlyengage a detachable blade, and have also been passed through separate bushings which had a flat surface adapted to press agalnst a blade. The former scheme does not accomplish the desired uniformity ofexpansion effect nor as firm a seating of the blade whereas the latter is unduly expensive of manufacture and besides requires more trouble in assembly.

I propose to provide a cutter head with tapped openings communicating with one set of slots and instead of driving in wedge pins provide expansive screws for cooperation with the tapped openings, the screws being integrally provided near their heads with a smooth tapered section purposed to spread apart the walls of the slot between which it enters. v Y

Adverting to the drawings? Figure I is a side elevation of a mllling cutter.

Fig. II is a plan view of Fig. I.

Fig. III is a vertical section taken on line 111 111 of Fig. 11.

Fig. IV is a fragmentary plan view showing one modification of my invent on.

Fig. V is a fragmentary plan view of another modified form.

Specification of Letters Patent. P te t t, 2 1921 Application filed November 11.11 920. Serial No. 423,224.

v F i VI is a fra enta vertical section %f Fig. VJ ry A cutter head 1 is fashioned with peripheral slots 2 in which are fitted blades 3. Between certain, in this instance between each, pair'of blades the head 1 is fashioned with additional somewhat narrower slots 4 each of which communicates at its middle with a conicall-y surface bore 5 Extending from the bottom of each of the bores 5 is a taped 0 eningv 6 the threads of which are adapted or cooperation with the threaded shank 7 of an expansive screw having a tapered head 8 adapted to fit the bore 5. The top of each screw is provided with a screw slot 9 to enable insertion and withdrawal of the screw by means of the screw drlver. I believe that the application of a screw for the purpose of spreading the resilient metal between any pair of blades is an improvement in the art, because it enables the binding action upon all the blades to be more uniformly affected by noticing the predeterminable amount of insertion movement of any particular screw and then successively imparting the same amount of movement to all the other screws.

When very wide cutters are made it is preferable to employ a plurality of expansion screws, and in Fig. IV I have shown each slot 4 to be intersected by three screws 10. Figs. V and VI merely show a modification consistin of the substitution of a square key hole in the head of each screw. Such screws 11 have heads 12 fashioned with squared holes 13.

I claim 1 1. A milling cutter comprising a metal head fashioned with separated slots whereby to impart a limited resilience to a portionv of said head between said slots, a

blade wholly'occupying one of said slots,

its outer end defined by a conical wall,'and a screw provided with a tapered head and itself adapted during'its-insertion move ment to spread the walls of the'slot which communicates with said opening. a

3. A milling cutter comprising a hea fashioneol'with a pair of slots each extending across 'fromfone side of the head to V the other side and'opening through its pe ripheral surface, a blade occupying one of said slots, said head being" also "fashioned with a partially tapped hole merging with the other of said slots, and a screw occupying' said holeand provided with a wedge section adapted When driven home directly to spread apart the walls of the slot which communicates with 7 said hole whereby to EDWARD A; COWLES. 

